On Wed, Jun 20, 2018 at 01:43:10PM -0600, Rob Herring wrote:

On Sun, Jun 17, 2018 at 08:49:47PM +0800, Dong Aisheng wrote:

quoted

The Messaging Unit module enables two processors within
the SoC to communicate and coordinate by passing messages
(e.g. data, status and control) through the MU interface.

Cc: Shawn Guo <shawnguo@kernel.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: Fabio Estevam <redacted>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: devicetree@vger.kernel.org
Signed-off-by: Dong Aisheng <aisheng.dong@nxp.com>
---
v1->v2:
 * typo fixes
 * remove status property
 * remove imx6&7 compatible string which may be added later for
   the generic mailbox binding

Note: Because MU used by SCU is not implemented as a mailbox driver,
Instead, they're provided in library calls to gain higher performance.

Using a binding doesn't mean you have to use an OS's subsystem.

What needs higher performance? What's the performance difference? Why 
can't the mailbox framework be improved?

From what I see the performance is improved by polling the interrupt

registers rather than using interrupts.
I see no reason though why this can't be implemented with the mailbox
framework as is.

Sascha

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